build: Use ls -i | cut rather than stat -f %i to extract inode

[imp]

Summary

ls -i dates back to 5th edition Unix and is more portable than the stat
command, though %% is a newer shellism, it works on any shell that
FreeBSD builds with.

Sponsored by: Netflix

[arichardson]

Both of these features are required by POSIX, %% also seems to be required:
https://pubs.opengroup.org/onlinepubs/009604499/utilities/xcu_chap02.html#tag_02_06_02

Does this mean the build no longer requires the stat command?

[imp]

In D43443#990386, @arichardson wrote:

Both of these features are required by POSIX, %% also seems to be required:
https://pubs.opengroup.org/onlinepubs/009604499/utilities/xcu_chap02.html#tag_02_06_02

Does this mean the build no longer requires the stat command?

Yes. That's my belief. I did the patch a few months ago.

[imp]

Landed 1461f1ec3adcc27c5605ac63b5fed94006c66202 w/o git arc stage accidentally.